Wood-preservative and process of making same.



' Lasagna.

No Drawing.

JUDSON A. DE GEW, OF MCNTREAL, QUEBEC, CANADA,

WOOD-PRESERVATIVE AND PROCILSS, OF MAKING SAME' To all whom it may concern: f Be it known that I, Jonson A. G:ew, a subject of the King of Great Britain, and resident of the city of Montreal, in the Province of Quebec and Dominion of Canada, have invented certain new and useful Improvements in. Wood-Preservatlves and Processes of Making Same, of which the following is a full, clear, and exact descr ption. This invention relates to the treatment of wood fiber by impregnation for the purpose of preserving, hardening and rendering the wood fiber more resistant to mechanical wear or to destruction by other agents.

I have discovered that I can dlssolvea large proportion of rosin and creosote 011 m a relatively small uantity of a more con centrated solution 0 rosin soap, and that by diluting this solution by special means, the free rosin in oil can be retained in either true or colloidal solution in the dilutedmixture My invention consists essentially in pre paring a composition for impregnating or treating wood or fibre-cellulose materlal said composition consisting substantially of rosin and creosote oilby first dissolving this composition in a soap solution such as rosin soap, the rosin and oil being either in true solution or colloidal solution depending upon theaqueous concentration or dilution of the soap. The amount of dilution or concentration of this composition will depend upon the amount of preservative which it is desired to leavewithin the wood to be treated. For instance, in vthe impregnation of wood blocks for pavements, I will use a more concentrated solution of soap and a higher proportion of free rosin and oil than in treating timber, which is merely to be made water resistant and sterile to prevent the growth of fungi. When it is only desired to preserve wood material from decay, I use a fairly dilute solution of rosin and oil in rosin soap, for in this process the lighter or more toxic creosote oils can be used and in very small quantity if only required to preserve the wood from decay.

It is recognized from oficial tests that one-third of a pound of creosote oil per cubic foot of wood is suiiicient, when properly distributed, to preserve timber from decay. It is also known that the lighter creosote oils having a specific gravity of less than 1 have double the toxic value of the heavier creosote oils. By-my process of obtaining colloidal solutions, I can obtain wood fibers to a much also partially decomposed Specification of Letters Patent. -Pa 'tgn1tedl t, 29, 1191s,, Application filed May e, 1916. Serial no. 95,468.

sufiicient preserving action by leaving onesixth of a pound of light creosote oil within a cubic -foot of wood. This creosote oil penetrates and covers the cell walls of the greater extent, owing to, the fact that it is in either true or colloidal solution in rosin soap during the impregnation process. On treating the wood bers by impregnation with these dilute aqueous solutions, the rosin and creosote oil.

become separated from the solution, and are deposited by adsorption on and within the cell walls of the material. The rosin soap solution, which has acted as a carrier, is and will remain largely within the material, even if the latter is afterward exposed to leaching and washing conditions. When the material so treated becomes air dry, it also becomes very water resistant owing to the presence of rosin deposited throughout the material. The deposited rosin also exerts avdecided preservative action, but its chief function is I to hold and prevent the evaporation of the more volatile creosote, which being held permanently within the fibrous structure without loss by' evaporation renders the material permanently toxic.

According to my process, the rosin soap solution is made by boiling say 100 pounds of rosin with approximately 15 pounds of sodium carbonate and about 200 pounds of water. To this is added, from 50 to 100 pounds of rosin, and about the same quantity of creosote oil or other oil preservative. When this product has been diluted to a perfect solution, it is then diluted by any means such as will prevent the separation from solution of the dissolved ingredients, the amount of dilution dependingu-pon the percentage of material which it is desired to leave within the wood after impregnation. This method of dilution can be efi'ected by the well known Erfurt process, as disclosed in U. S. Reissue'Patent No. 12,549, or by other suitable means, such as forcing the solution under pressure into hot water and then cooling same.

By employing an injecting device operated by means of hot water under high pressure, dilute solutions can be obtained without the separation of the dissolved rosin and oil mixture. In this manner, solutions containing as low as 1 or 2% of total solids can be produced. These dilute solutions will stand a reasonable amount of heating without decomposition, and; can be forced into fibrous material under pressure in an apparatus similar to that used 1n ordmary/woodand will harden,

preserving processes. This wood preserving composition-is very advantageous in that it is neutral and non-corrosive, and will not cause such destruction of the timber as follows from the use of chlorid of zinc, sulfate of alumina and other preservative metals. resists the penetration or infiltration of water, which tends to wash out water soluble substances, and the preservative will therefore not be lost on exposurein wet climates; This preservative will also be more uniformly strengthen and increase the density of the fiber, making it more resistant to mechanical wear. By my process, a ver volatile toxic oil may be employed WhlCh could not be successfully used by other rocesses. Although in carrying out my process, it is not necessary usually to follow it with any secondary treatment, yet in special cases, the wood impregnated with the above described solution may be treated with weak solutions of a coagulant, such as sulfate of alumina,

firmly fix all of the rosin which will more soap within the fiber, thus completely plugging the cell openings in the woody material.

. Having Furthermore, the treated material distributed throughout thewood,

Iclaimiszv v, .1. A process of making wood preservative,

which consists in dissolving a toxic oil ina soap solution and diluting same by forcing under pressure into hot water. 2. A wood preserving composition,

aqueous solution. ,7

' 3. 'A wood preservative consisting of toxic oil in a'state of colloidal suspension, the dis ersion medium being a dilute aqueous soution containing a saponified product, the y dlspersion having been produced by forcing the undiluted mixture into hot water by --means of pressure. r

4. Awood preserving composition, which consists of creosote oil which has beendissolved in a. soap solution containing free rosin, and further diluted in water to form a non-separating compound. 5. A process of making wood preservative,

which consists in dissolving rosin and creo-' sote o1 l 1n a soap solutlon, and. dlluting same by forcing it under pressure into'liot water. In witness whereof, I have hereunto set my hand, in the presence of two witnesses. JUDSON A. DE CEW.

Witnesses: v

FREDERICK B. BRO N, P. MrRUsHMoRE.

thus described my invention, what 0 which -cons1sts of rosm, creosote 011 and-soap 1n 

